Location based services (LSB) such as traffic monitoring/regulation commonly use the GPS (Global Positioning System) to locate and track vehicles in a geographic area. One vehicle location method and system using GPS for collision avoidance purpose is disclosed in U.S. Pat. No. 5,450,329 to Tanner. One method for undertaking context-dependent actions based upon GPS service is disclosed in US 2006/0129309 (Alewine).
However the known techniques for tracking moving entities, because they are based upon sophisticated and precise positioning systems (typically GPS), require important processing power and large network architectures, which are generally over-dimensioned vis-à-vis the end-task, typically traffic information or routing services to be delivered to the subscribers.
In addition, the known tracking techniques are generally passive, i.e. the moving entities are simply periodically requested to state variable parameters such as geographical coordinates (and, possibly, speed), in order for the core program (e.g. implemented on a server connected to a localization server) to calculate the predicted path of each entity.
It is the inventors' opinion that the known tracking techniques fail to efficiently track a population of entities, thereby reducing the capability of the tracking system to positively act on the context.